This article is a brief introduction to traditional Chinese medicine tongue diagnosis. Tongue diagnosis is an important part of diagnosis in Chinese medicine, which refers to the inspection of the shape, size, color and moisture of the tongue’s body and its coating or fur to diagnose disease.
Why can we use the tongue as an evidence of diagnosing diseases?
In order to answer this question, we need to understand the basis of tongue diagnosis in traditional Chinese medical theory.
The tongue is closely related to the Zangfu organs. The heart opens at the tongue, the movement of the tongue is controlled by the Heart Spirit. The Spleen meridian or energy channel connects with the tongue and the taste sensation of the tongue is mainly dominated by the spleen, and there are many other descriptions in Chinese medical theories.
The tongue is also nourished by Qi and Blood and it is moistened by Body Fluids. The tongue, therefore, can reflect the condition of Zangfu organs, Qi, Blood and Body Fluids. An examination of the tongue is extremely important in diagnosis, treatment, prognosis and prevention of diseases.
What should we inspect when doing tongue diagnosis?
Inspection of the tongue mainly includes the examination of the body of the tongue and the coating or fur of the tongue. Tongue body refers to the musculature and vascular tissues of the tongue, also referring to tongue substance. Inspection of the tongue body includes examining the color, shape, texture and movement of the tongue, which reflect the condition of the Zangfu organs, Qi, Blood and Body Fluids.
Tongue coating is a layer of moss-like material covering on the surface of the tongue. Inspection of the tongue coating includes examination of the texture and color of the tongue coating. Therefore, pathologically, tongue coating reflects the location and nature of diseases, as well as the condition of healthy Qi.
Now, let’s take a look at what a normal tongue looks like.
Appearance of a normal tongue.
The normal tongue body is soft, flexible, pale red, and not too large and not too small. The normal tongue coating is white and thin, and is neither dry nor greasy or slippery. The coating is closely attached to the surface of the tongue, distributed more on the center and root, but less on the margins and tip.
The normal tongue is usually described as “pale-red tongue with thin and white coating,” which suggests normal functions of the Zangfu organs, sufficient Qi, Blood and Body Fluids.
Why is tongue diagnosis so important in TCM clinical practice?
We need to understand this from its five aspects of clinical significance.
The clinical significance of tongue diagnosis
The first aspect, indicating exuberance and debilitation of healthy Qi and pathogenic Qi.
Generally, healthy Qi manifests on the tongue’s body and pathogenic Qi mainly manifests on the tongue coating. A pale-red and flexible tongue means that healthy Qi is exuberant, Qi and Blood is abundant and flow smoothly.
A tongue that is palemay suggest Blood and Deficiency. Thin, white and moist coating means no morbid condition on the patient, or the pathogenic Qi is not severe; thick coating means pathogenic Qi is exuberant.
Second aspect, distinguishing the nature of disease.
Tongue manifestation can reflect the nature of diseases. For example, thin, white coating indicates wind–cold external contraction; white and slimy coating indicates phlegm – dampness retention.
Third aspect, differentiating the degree of disease.
The degree of illnesses can reflect on the tongue fur or coating, while the severity of disease may manifest on both tongue body and tongue coating. For example, during external contracted disease, a thin and white coating indicates the early stage of the disease. Red tongue with yellow and thick coating suggests that the pathogen has entered the interior Qi aspect and the condition is morbidly severe.
A crimson tongue indicates that the pathogen has reached the nutrient aspect. Finally, a dark and purple tongue with little or without coating indicates that the pathogen has entered the Blood aspect.
Fourth aspect, the changes in the tongue can also indicate progress of the disease.
If the coating color changes from white to yellow, from yellow to black, or the tongue furgoesto thick from thin, or from moisture to dryness, this indicates that the pathogen has entered the interior, the disease has changed into severe, the disease changes from cold into heat syndrome, all leading to fluid damage.
On the other hand, if the tongue fur changes from thick to thin, from yellow to white, or from dryness to moisture, it means the disease is getting better.
Fifth aspect, the changes in the tongue also can indicate prognosis of disease.
Luxuriant tongue with normal movement and white thin coating indicates pathogenic Qi is not exuberant, healthy Qi is still sufficient, stomach Qi is still strong and the patient’s prognosis is favorable. Withered tongue with abnormal movement and tongue coating has no root, indicates deficiency of healthy Qi and debilitation of stomach Qi. This means the patient’s condition is critical.
Through the observation of the tongue, many physiological conditions and pathological changes in the body can be detected. TCM tongue diagnosis is easy to perform and tongue manifestation can reflect disease.
Why don’t you spend several seconds to take a look at your tongue when you look at yourself in the mirror every day, not only for your beauty but more importantly, for your health!